Joint brace with improved range of motion stop

ABSTRACT

An improved joint support for limiting the range of motion of an anatomical joint comprises intermeshing gears for allowing adjustment of the range of motion of the joint, and comprises plural mechanisms for securing the gears in engagement with one another, whereby adjustment can be made without tools and without disassembly of any components.

FIELD OF THE INVENTION

This invention relates to an improved joint brace for an anatomicaljoint, such as the fetlock of a horse, which is provided with convenientand reliable adjustment for the range of motion (ROM) permitted to thejoint. This is useful during training, for rehabilitation after injuryor surgery, and otherwise.

BACKGROUND OF THE INVENTION

The present inventors and others have filed several generally relevantprior applications, including Ser. No. 61/321,212, filed Apr. 6, 2012,Ser. No. 13/064,644, filed Apr. 5, 2011, now U.S. Pat. No. 8,894,594,Ser. No. 13/694,621, filed Dec. 18, 2012, now U.S. Pat. No. 9,044,306,and Ser. No. 14/106,300, filed Dec. 13, 2013. Priority from these priorapplications is not being claimed at the initial filing of thisapplication, although applicant reserves the right to later claimpriority therefrom if deemed necessary.

Of the above, Ser. No. 14/106,300 is the most recent, and the mostrelevant to the present invention. Ser. No. 14/106,300 discloses a jointbrace with an adjustable ROM stop, as does this application. Theadjustable ROM stop of the present invention, and the joint braceemploying it, are novel and unobvious over that shown by Ser. No.14/106,300.

More specifically, FIGS. 33-36 of Ser. No. 14/106,300 disclose a jointbrace, optimized to support the fetlock of a horse, incorporating a ROMstop as well as resilient members adapted to add to the ability of thehorse's joint structure to support it as the joint moves in extension.FIG. 37 discloses the ROM stop without the resilient members. The ROMstop of the present invention is likewise useful in connection withjoint braces both with and without resilient members.

For convenience, FIGS. 33-37 of Ser. No. 14/106,300 (published asapplication 2014/0148746) are reproduced in this application as FIGS.1-5, respectively. The text describing these is reproduced below, withthe figure numbers corrected accordingly, as follows:

“FIGS. 1-3 show a further refinement, employing the same structure asexplained above with respect to FIGS. 31 and 32, but incorporating aswell a range of motion (ROM) stop. Limiting the range of motion of thejoint can be helpful in rehabilitation of musculoskeletalstructures—again, both hard and soft tissues—after injury or surgery.Early return to function is pivotal to the patient's successful recoveryfrom injury. Some early range of motion exercises help attenuateadhesive scar tissue formation, promote more normal tissue formation,and thereby increase functionality. Muscle atrophy is also less thanwould occur if the lower limb was completely immobilized. However,unrestricted exercise is counterproductive, setting the stage forreinjury or new lesion formation and a more prolonged and possiblyunsuccessful outcome. Adjustment of the ROM to optimize it to thepatient's specific recovery status is desirable; generally, as thepatient recovers, the ROM can be gradually increased.

“This is accomplished in the embodiment shown by providing a ROM stopmember 216, held to pin 204 (FIG. 4) by a screw 220. As shown by theexploded view of FIG. 1, a gear wheel 218 having external teeth 218 a iskeyed to the lower cuff 202. The ROM stop member 216 has internal gearteeth (not shown) which mate with the external teeth of gear wheel 218.The mating internal and external peripheral teeth shown could bereplaced with radial teeth on the mating faces of the ROM stop member216 and the lower cuff 202. ROM stop member 216 also comprises an arm216 a, which is arranged to bear against stop 214 on the upper cuff 200.Thus, as the joint is extended, ROM stop member 216 rotates along withlower cuff 202 until arm 216 a contacts stop 214, limiting the ROM ofthe joint. As the patient recovers, and increased ROM becomes desirable,the relative position of ROM stop member 216 with respect to lower cuff202 can be adjusted simply by removing screw 220, removing ROM stopmember 216 sufficiently to disengage the teeth from one another, turningit counterclockwise and replacing it in its new position.

“There are numerous alternative designs for the ROM stop that will occurto those of skill in the art, and are to be considered within the scopeof the invention. These include a non-extensible cord, extending betweenthe fixing points of the resilient tension member 212, and of lengthappropriate to limit the ROM as desired. Adjustment of ROM could beprovided by use of cords of different lengths, or providing a choice offixing points that would provide differing effective lengths. The cordcould also be provided in the form of a tubular length of webbing,possibly encasing the resilient tension member 212. Other alternativesinclude a plate affixed to the upper cuff 200 in the approximateposition of stop 214, with a number of holes for receiving a stop pinthat would bear against a block on lower cuff 202; by provision of anumber of holes for the stop pin, the ROM could be adjusted.

“It is also desirable to provide adjustment of the tension exerted bythe resilient tension member 212; for example, as the joint recoversfrom injury or surgery, it may be desirable to gradually reduce thetension exerted for a given degree of joint flexion. This can beaccomplished in a variety of ways. For example, one or more of the flatribbons 212 c of the resilient tension member 212 can simply be cutaway. Different resilient tension members 212 having differentcharacteristics can be employed, or multiple resilient tension members212 can be employed initially, and be removed progressively as the jointrecovers. The attachment point of the resilient tension member 212 oneither upper cuff 200 or on wing member 210 can be varied, as can thedesign of the wing member 210; if the wing member 210 is effectivelylengthened, e.g., by proving multiple attachment points along itslength, more tension will be exerted for a given degree of jointextension. Likewise, the point at which the resilient tension member 212begins to exert tension and support the joint can be varied as desiredby variation of the geometry of the device.

“It will also be appreciated by those of skill in the art that thefunction of resilient tension member 212 could be provided by othertypes of devices, such as tension, compression, leaf, hairpin or torsionsprings. The cord containing a dilatant material discussed above withrespect to FIG. 16 could also be employed. These are to be consideredwithin the meaning of “resilient tension member” except where thecontext or explicit language excludes such alternative devices.

“It is also within the scope of the invention that the device could alsobe made such that the resilient tension members on either side of thebrace could be adjusted independently of one another. For example, itmay be desirable to provide more tension on one side than the other whenthe injury is asymmetric.

“As noted, the embodiment of FIGS. 31 and 32 includes the resilienttension member for assistance in bearing the tensile loads on thetendons, while the embodiments of FIGS. 1-3 add to this the ROM stopfeature. It is also within the scope of the invention to provide the ROMstop feature without the resilient tension member; this could also beuseful in rehabilitation. FIG. 5 shows modification of the device shownto include the ROM stop only. As illustrated, again a ROM stop member216 is secured to the lower cuff by an arrangement allowing adjustmentof their relative radial positions. ROM stop member 216 comprises an arm216 a arranged to bear against a stop 214 secured to the upper cuff200.”

Thus, as indicated above, Ser. No. 14/106,300 discloses a joint supportincorporating a ROM stop. The present application does so as well, butincorporates further improvements in the ROM stop.

SUMMARY OF THE INVENTION

The specific improvements made by the present invention relate toadjustment of the ROM permitted. In the embodiment disclosed by Ser. No.14/106,300, the adjustment is made by removing a small screw 220,freeing ROM stop member 216, pulling ROM stop member 216 axiallyoutwardly sufficiently to disengage internal gear teeth formed on theinside of ROM stop member 216 from external teeth of gear wheel 218,turning the ROM stop member 216 in the desired direction(counterclockwise in order to increase ROM, in the FIG. 1 view)replacing it in its new position, and securing it with screw 220.

It will be apparent that this procedure requires a screwdriver or othertool, and that in the typical barnyard or horse stall it would be easyto lose the screw 220, particularly if the horse should move while oneis attempting to reinsert the screw 220. Even if the screw were replacedby another fastener that could be operated by hand, such as athumbscrew, the screw could nonetheless come loose during exercise,allowing the ROM stop assembly to fall off, which could lead tooverextension of the joint and possible injury. It is therefore anobject of the invention to provide a ROM stop that can be adjustedwithout tools, and without any components becoming detached.

According to the invention, the cooperating gears which determine theROM are secured in their operative position by a sliding latch lockingstructure, operable by hand, so as to eliminate the possibility of theremovable portion of the assembly becoming accidentally detached. One ormore magnets retained in the assembly so as to avoid being lost mayadditionally be provided; these require application of force to “unlock”the ROM adjuster, reducing the possibility of the device's coming looseduring exercise.

Another object of the invention is to provide a directly-readable scaleindicating the ROM permitted, so as to simplify adjustment. This isaccomplished according to the invention by provision of cooperatingindicia around the periphery of the adjustable portion of the assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood if reference is made to theaccompanying drawings, in which:

FIG. 1, corresponding to FIG. 33 of Ser. No. 14/106,300, shows aperspective view of the prior art joint support, showing the ROM stop inpartially exploded view, with the joint straight;

FIG. 2, corresponding to FIG. 34 of Ser. No. 14/106,300, shows a viewsimilar to FIG. 1, and of the same embodiment, with the joint extended;

FIG. 3, corresponding to FIG. 35 of Ser. No. 14/106,300, shows anenlarged view similar to FIG. 1, with the device assembled;

FIG. 4, corresponding to FIG. 36 of Ser. No. 14/106,300, is across-sectional view taken along the line B-B of FIG. 3;

FIG. 5, corresponding to FIG. 37 of Ser. No. 14/106,300, is a viewsimilar to FIG. 1, illustrating a further modification;

FIG. 6 shows a perspective front view of the joint brace of theinvention, incorporating the improved ROM stop;

FIG. 7 shows a perspective rear view thereof;

FIG. 8 shows an enlarged detail view taken at A in FIG. 7;

FIG. 9 shows an exploded view of the ROM stop of the invention, from thelateral side;

FIG. 10 shows an exploded view of the ROM stop of the invention, fromthe medial side;

FIG. 11 shows an enlarged exploded view of the ROM stop assembly, which,as will be discussed in detail below, is moved axially outwardly androtated to adjust the ROM permitted;

FIG. 12 shows a perspective view of the ROM stop assembly, showing theinterior thereof;

FIG. 13 shows a perspective view of the ROM stop assembly, showing theexterior thereof;

FIG. 14 shows an elevation of the joint brace of the invention;

FIG. 15 is a side view of the joint brace of the invention;

FIG. 14 shows an elevation of the joint brace of the invention;

FIG. 15 is a side view of the joint brace of the invention;

FIG. 16A is a cross-sectional view taken along the line 16-16 of FIG.15, with the sliding latch in the closed position;

FIG. 16B is a comparable cross-sectional view taken along the line 16-16of FIG. 15, with the sliding latch in the open position;

FIG. 17A is a cross-sectional view taken along the line 17-17 of FIG.15, with the sliding latch in the closed position;

FIG. 17B is a similar cross-sectional view taken along the line 17-17 ofFIG. 15, with the sliding latch in the open position; and

FIG. 18 is an elevation and FIG. 19 a cross-sectional view of a pivotaxle, provided separately for clarity of the other views.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As indicated above, it is an object of the invention to provide a jointbrace with an improved ROM stop mechanism permitting the ROM to beadjusted without tools, and without any disassembly, so that partscannot be lost and the ROM can be adjusted conveniently. It is a furtherobject of the invention to provide readily-visible indicia that describethe ROM provided, for convenience and consistency of the ROM setting.

These objects are met by the joint brace and improved ROM stop mechanismof the invention, as will appear below.

As in Ser. No. 14/106,300, the joint brace comprises upper and lowercuffs secured to the anatomical structure on either side of the joint tobe protected, and pivoted to one another at medial and lateral pivotpoints so as to define a pivot axis approximately coinciding with theanatomical joint. Cooperating stop members secured to the upper andlower cuffs abut on extension of the joint to limit the ROM of thejoint. The ROM is adjusted by adjustment of the point at which thecooperating members abut.

Also as in Ser. No. 14/106,300 a fixed stop is secured to one of theupper and lower cuffs, and an adjustable ROM stop to the other of theupper and lower cuffs. The adjustable ROM stop is provided on an outergear with internal teeth, while an inner gear with external teeth isfixed to the other of the upper and lower cuffs. Adjustment of ROM isaccomplished by moving the outer gear axially outwardly to disengage itfrom the fixed gear, permitting repositioning.

As will be apparent, for the joint brace to function properly to limitROM, the components must be securely fastened to one another so as tonot become disengaged in use. In Ser. No. 14/106,300 this wasaccomplished using a single screw. This allowed the possibility that thescrew could come loose or be lost, and the screw might be difficult toreinsert under some circumstances.

According to the present invention, a mechanism is provided to securethe components of the brace in the desired position to control ROM,while permitting adjustment to be made without disassembly, and withouttools. A first securing mechanism includes a hand-operable sliding latchmechanism that positively locks the components in the desired position,but can be readily released to allow adjustment of the ROM. A secondsecuring mechanism employs magnets to secure the components of the ROMstop mechanism to one another.

In the following, we describe the joint brace comprising the improvedROM stop mechanism of the invention. Common components are commonlynumbered, and the features of the invention most clearly illustrated bythe various views will be described with respect to each.

Thus, FIGS. 6, 7, 14 and 16 show views of the complete joint brace, andFIG. 8 shows a detail of FIG. 7 at larger scale, for clarity. FIGS. 6and 7 show the brace as employed to limit the ROM of a horse's fetlock,but it will be appreciated that the joint brace of the invention wouldbe useful with other anatomical joints, including human.

The joint brace 300 comprises an upper cuff 302 secured to an uppermember of the joint the ROM of which is to be limited (in the case of ahorse's fetlock, the cannon bone), by straps 304, and a lower cuff 306secured to the other member of the joint (in the case of a horse'sfetlock, the pastern bone), by a strap 308. Cuffs 302 and 306 may bemolded of a tough plastic material or the like.

The upper and lower cuffs 302 and 306 respectively are joined to oneanother by way of upper and lower side plates 310 and 312 respectively,which are provided on both medial and lateral sides of the joint brace300. The ROM stop mechanism need only be provided on one side of thejoint brace 300; as illustrated, it is typically employed only on thelateral side, so as to avoid interference with the horse's opposite leg.

The upper and lower cuffs 302 and 306 respectively are joined to theupper and lower side plates 310 and 312 respectively by rivets or otherfasteners, as indicated at 314 (FIG. 15).

The upper and lower side plates 310 and 312 respectively are secured toone another so as to pivot freely about a pivot axis that issubstantially aligned with the anatomical joint to be protected. Thestructure defining the lateral pivot axis between the upper and lowerside plates 310 and 312 respectively is shown in detail, and forms apart of the ROM stop assembly, as will appear below; the medial pivotstructure is generally similar.

The structure defining the lateral pivot axis between the upper andlower side plates 310 and 312 respectively comprises a central pivotaxle 316. In the embodiment shown, pivot axle 316 is radially symmetric,so that it can be turned from a cylinder of metal or plastic (dependingon the use; a joint brace for a horse's fetlock will likely need to bemade of metal, while one for, for example, a human wrist could be madeof plastic), or molded in a single piece. The detailed structure ofpivot axle 316 is shown separately in FIGS. 18 and 19, so as to avoidcluttering the other drawings with excessive reference numerals.

Thus, as shown in FIGS. 18 and 19, the outer surface of pivot axle 316is formed to define a medial bearing surface 316 a of a first diameter,having a snap-ring groove 316 f therein, an intermediate bearing surface316 b of larger diameter than medial bearing surface 316 a, a latchingrecess 316 c of reduced diameter, an outer locating surface 316 ddefining a locking shoulder 316 k, and a bore 316 e. The inner surfaceof bore 316 e is further formed to define bushing recesses 316 g and 316h, pin bearing surface 316 i, and an inner locating surface 316 j.

As shown in the cross-sectional views of FIGS. 16A and B and FIGS. 17Aand B, the lower side plate 312 is formed to define a stepped bore 312a, so that when the pivot axle 316 is inserted into bore 312 a, lowerside plate 312 is located by the intersection of the stepped bore 312 awith the junction of medial bearing surface 316 a and intermediatebearing surface 316 b: This can be a press-fit, so that lower side plate312 and pivot axle 316 rotate together with respect to upper side plate310. Upper side plate 310 fits over the inner end of inner bearingsurface 316 a, with a bushing 318 interposed therebetween, to permitfree rotation. The assembly of upper and lower side plates 310 and 312and pivot axle 316 is made permanent by a snap-ring 320 fitting intosnap-ring groove 316 f.

If the upper and lower side plates 310 and 312 respectively are made ofa material tending to gall, such as if they were machined or cast ofaluminum, a thrust washer 322 made of a low-friction plastic materialsuch as acetal may be interposed therebetween. Washer 322 can beretained in position by a spring pin 324 received in mating bores inwasher 322 and upper side plate 310. If the upper and lower side plates310 and 312 are made of a non-galling material, such as if molded ofplastic, thrust washer 322 can be omitted.

The same pivot joint structure, with the pivot axle 316 cut off at theright side of the intermediate bearing surface 316 b (referring to FIGS.18 and 19) can be used on the medial side of joint brace 300 to join themedial upper and lower side plates 310 and 312.

In accordance with the objects of the invention, the range of motion(ROM) permitted by the joint brace 300 of the invention is to be readilyadjustable to allow convenient variation of the ROM, for example as apatient recovers from injury or surgery.

Limitation of the ROM is provided by cooperating stop members secured tothe upper and lower side plates 310 and 312 which abut to preventfurther relative rotation, thus limiting the ROM. Adjustability of theROM is provided by making one of the stop members movable with respectto the corresponding side plate. In the embodiment shown, a stop member326 is fixed to upper side plate 310, while a stop member 328 isassembled to lower side plate 312 in a manner such that its orientationcan be readily adjusted to allow selection of a desired ROM. However,the relative disposition of these functions could be reversed, and thisis to be considered to be within the scope of the invention.

As illustrated, upper stop member 326 may comprise a pad 326 a of a hardrubber or like resilient material, to absorb the shock of the stopmembers coming into contact with one another.

To provide relative angular adjustment of the positions of stop members326 and 328, cooperating gears 330 and 332 are provided. Gear 330 hasexternal teeth and gear 332 internal teeth 332 a, of the samespecification, so that when the teeth of the gears 330 and 332 areengaged, relative motion thereof is prevented. Gear 330 is fixed tolower side plate 312 by pins 334, while gear 332 is formed integrallywith or fixedly assembled to stop member 328. Thus, when gear 332 isintermeshed with gear 330, and the lower cuff 306 is rotated togetherwith lower side plate 312 as the fetlock is extended—that is, uponclockwise rotation of the lower cuff 306 in the view of FIG. 6, forexample—the ROM of the joint is limited when stop member 328 abuts stopmember 326.

As above, ready and convenient adjustment of the ROM permitted, withouttools and without the possibility of losing parts, is an object of theinvention. Adjustment is provided in the following way: gear 332 issimply moved axially outwardly out of engagement with gear 330, theassembly of gear 332 and stop member 328 rotated to the desiredposition, and gear 332 resecured in engagement with gear 330.

The mechanism whereby gear 332 can be conveniently released fromengagement with gear 330 and resecured thereto after adjustment asdesired is accordingly an important aspect of the invention. This isaccomplished as follows.

The principal mechanism for releasably securing the gears 332 and 330 inengagement with one another comprises a sliding latch 336. As shown mostclearly in FIG. 11, sliding latch defines a generally racetrack-shapedaperture—essentially having two semi-circular ends separated by straightsections—indicated at 336 a and closed by a lower engaging member 336 b.Sliding latch 336 slides in a passageway 338 c defined by opposedparallel walls 338 a formed in a molded slider assembly cap 338, and isbiased outwardly by a spring 340 received in a recess 338 b in a sliderassembly cap 338. A contoured outer contact surface 336 c is provided toreceive a user's finger, to press sliding latch 336 inwardly against thebias of spring 340. Sliding latch 336 is confined in passageway 338 c,and spring 340 in recess 338 b, by a slider assembly plate 342. Gear 332and slider assembly plate 342 are secured to slider assembly cap 338 bypins 344, forming a unitary ROM stop assembly 346 in which the onlymoving parts are sliding latch 336 and spring 340. An outer decorativecap 358 completes the ROM stop assembly 346.

As shown by the cross-sectional views of FIGS. 16A and B, and FIGS. 17Aand B, the ROM stop assembly 346 is assembled to the assembly of pivotaxle 316 and upper and lower side plates 310 and 312 by a headed pin 348received in a central bore in slider assembly cap 338, and having acirclip groove 348 a at its medial end. Pin 348 may be secured to sliderassembly cap 338 when the latter is molded. Groove 348 a passes throughthe bore in axle 316 and receives a circlip 350 to secure the ROM stopassembly 346 to the assembly of upper and lower side plates 310 and 312.Medial and lateral bushings 351 and 353 respectively are preferablyprovided between pin 348 and pivot axle 316. Pin 348 fits slidinglywithin central pin bearing surface 316 i of axle 316.

As also shown by the cross-sectional views of FIGS. 16A and B, and FIGS.17A and B, pivot axle 316 fits within aperture 336 a of sliding latch336. As can be seen by comparison of FIGS. 16A and B, in the lockedposition of FIG. 16A, the lower engaging member 336 b of latch 336 fitswithin latching recess 316 c of axle 316, bearing against lockingshoulder 316 k, and held in this “locked” position by spring 340, thussecuring the ROM stop assembly 346 such that gears 330 and 332 areintermeshed, preventing relative rotation thereof and thereby fixing theposition of stop member 328. Accordingly, in order to adjust the ROMpermitted, the sliding latch is pushed in by one's finger, against thebias of spring 340, disengaging lower engaging member 336 b of latch 336from latching recess 316 c of axle 316, to take an “unlocked” position,as shown by FIG. 16B. The ROM stop assembly 346 can then be pulledaxially outwardly, disengaging gears 330 and 332 from one another, tothe position shown in FIGS. 16B and 17B, rotated to the positiondesired, and moved in the medial direction, back to the locked position.The distance through which ROM stop assembly 346 can thus be pulledaxially outwardly is controlled by the spacing between circlip 350 andthe medial end surface of medial bushing 351. When the ROM stop assembly346 again reaches its original locked position as shown in FIGS. 16A and17A, spring 340 urges sliding latch 336 outwardly, such that lowerengaging member 336 b of latch 336 again engages latching recess 316 cof axle 316, securing ROM stop assembly 346 in the locked position.

It will be apparent that it would be possible, albeit unlikely, for aclod of dirt, a stone or a stick to be thrown up during exercise of ahorse fitted with the joint brace of the invention in such a way as todepress sliding latch 336 and allow rotation of gear 332 with respect togear 330, thus varying the ROM permitted and possibly leading to injury.To prevent this, a second restraining mechanism is provided that keepsROM stop 346 in the locked position even after sliding latch 336 ismoved inwardly, that is, such that some amount of force must be exertedto move ROM stop assembly 346 axially outwardly after latch 336 isdisengaged from axle 316.

In the preferred embodiment shown, this additional restraining mechanismis provided by magnets 352, which are retained in cooperating recesses342 a in slider assembly plate 342 and 338 d in slider assembly cap 338.Magnets 352 are closely juxtaposed to gear 330 when the ROM stopassembly 346 is in the engaged position of FIGS. 16A and 17A, and exertan attractive force on gear 330, so that this force must be overcome byforce exerted by one's hand pulling outwardly on the ROM stop assembly346 in order to move gear 332 out of engagement with gear 330 and adjustthe ROM permitted. An additional restraint is thus provided.

This magnetic restraint requires that gear 330 at least comprise somequantity of, or be made entirely of, a ferromagnetic material, possiblyferromagnetic stainless steel. A different way of providing anadditional restraining mechanism would be to provide a spring 354 undera washer 356 and secured by the circlip at the medial end of pin 348.See FIG. 17A. This would likewise require axial outward force to beexerted in order to disengage gear 332 from gear 330 and would providean additional restraint. This alternative would also allow eliminationof magnets 352, would allow gear 330 to be made of a less expensive andlighter-weight material, e.g., to be molded of plastic, and would allowslider assembly plate 352 to be thinner, since it would not need todefine recesses 342 a for receiving magnets 352. On the other hand, oneadvantage of use of magnets as opposed to a spring is that the forceexerted by the magnets is reduced as the gear 332 is withdrawn, makingit easier for the user to hold the ROM stop assembly 346 in the unlockedposition; if a spring is used, the force required to hold the ROM stopassembly 346 in the unlocked position is increased as the ROM stopassembly 346 is withdrawn.

Again, the choice of materials for gears 330 and 332 will depend on theuse. In an equine application, these gears will likely need to be madeof metal; in a human application, they may be molded of plastic.

It will also be appreciated that the number of intermeshing teeth ongears 330 and 332 will control the number of choices of ROM madeavailable; if a 5° adjustment is desired, 72 teeth will be needed ongears 330 and 332.

The latch could also be provided in different form. For example, a leverpivoted about an axis perpendicular to the axis of the axle 316 andoff-center to one side of the slider assembly cap 338 could be employedto releasably secure gears 330 and 332 in engagement with one another.

Finally, as mentioned earlier one goal of the invention is to provideindicia indicating the amount of ROM permitted, so as to allowconvenient setting of the ROM by engagement of gears 330 and 332 at adesired relative position. This is accomplished as shown by Detail A inFIG. 8, and in FIGS. 11 and 12. A series 360 of numerals indicatingvarying amounts of degrees of ROM are stamped or engraved on the outercircumference of the gear 332, opposite a fiducial mark 362 on the lowerarm 312. As the gear 332 is rotated to set the ROM, a different one ofthe series 360 of numerals is disposed opposite fiducial mark 362,indicating the degree of ROM permitted.

As mentioned above, the ROM stop of the invention could also be employedin a joint brace also providing resilient members assisting insupporting the joint, as in FIGS. 1-3.

Therefore, while a preferred embodiment of the invention has beendisclosed in detail, the invention is not limited thereto, but only bythe following claims.

What is claimed is:
 1. A joint support device for limiting the range ofmotion of a joint disposed between proximal and distal sections of alimb, said joint defining an axis of rotation, said joint support devicecomprising: a proximal cuff, adapted to fit closely about said proximalsection of said limb, and be secured thereto; a distal cuff, adapted tofit closely about said distal section of said limb, and be securedthereto; said proximal and distal cuffs each being secured to respectiveproximal and distal side plates on both medial and lateral sidesthereof, said proximal and distal side plates comprising cooperatingbores for receiving medial and lateral pivot axles, such that saidproximal and distal side plates can be assembled to one another, therebydefining an axis of rotation of said joint support device substantiallyaligned with the axis of rotation of said joint; a first stop memberfixed to one of said proximal and distal side plates on at least one ofsaid medial and lateral sides, and a second stop member releasablysecured to the other of said proximal and distal side plates on said atleast one of said medial and lateral sides, said first and second stopmembers being located so as to contact one another upon extension ofsaid joint, so as to limit the range of motion of the joint; wherein thesecond stop member releasably secured to the other of said proximal anddistal side plates can be released therefrom, rotated in order to adjustthe range of motion of the joint to be permitted, and resecured thereto;and wherein said second stop member is releasably secured to the otherof said proximal and distal side plates member by a first mechanismoperable by a user without tools to release and resecure the second stopmember from the other of said proximal and distal side plates, and by asecond mechanism that requires the user to apply force to remove thesecond stop member from the other of said proximal and distal sideplates.
 2. The joint support device of claim 1, wherein the first stopmember is fixed to the proximal side plate and the second stop member isreleasably secured to the distal side plate.
 3. The joint support deviceof claim 1, comprising a first gear fixed to the other of said proximaland distal side plates and a second gear to which said second stopmember is fixed, said first and second gears being intermeshed with oneanother to secure said second stop member with respect to the other ofsaid proximal and distal side plates, and wherein said first and secondmechanisms are operated by a user to remove said second gear from saidfirst gear in order to adjust the range of motion of the joint to bepermitted.
 4. The joint support device of claim 3, wherein said firstgear is generally circular and has teeth on its outer periphery and saidsecond gear is of ring form and has intermeshing teeth on an innersurface of said ring, such that when said second gear is secured withinsaid first gear, said second stop member is fixed with respect to saiddistal side plate, and such that said second gear can be withdrawnaxially from within said first gear to adjust the range of motion ofsaid device.
 5. The joint support device of claim 4, wherein said firstmechanism operable by a user without tools to release and resecure thesecond stop member from the other of said proximal and distal sideplates comprises a latch that must be operated by a user against thebias of a spring in order to allow said second gear to be withdrawnaxially from within said first gear to adjust the range of motion ofsaid device.
 6. The joint support device of claim 5 wherein said latchcomprises a sliding latch pushed radially inwardly against the bias of aspring in order to allow said second gear to be withdrawn axially fromwithin said first gear to adjust the range of motion of said device. 7.The joint support device of claim 6, wherein said sliding latch issecured axially with respect to said second gear, and comprises agenerally racetrack-shaped aperture therein, fitting over a pivot axlehaving a locking recess terminated by a shoulder, whereby said slidinglatch bears against said shoulder to secure the second gear within thefirst gear, and whereby when said sliding latch is pushed radiallyinwardly, a distal portion of said latch is moved past said shoulder,allowing said sliding latch and the second stop member to be movedaxially outwardly.
 8. The joint support device of claim 7, wherein saidsliding latch is confined in a passageway defined between a sliderassembly plate and a slider assembly plate.
 9. The joint support deviceof claim 3, wherein said second mechanism that requires the user toapply force to remove the second stop member from the other of saidproximal and distal side plates comprises magnets that exert anattractive force urging said second gear into engagement with said firstgear.
 10. The joint support device of claim 3, wherein said secondmechanism that requires the user to apply force to remove the secondstop member from the other of said proximal and distal side platescomprises a spring biasing said second gear into engagement with saidfirst gear.
 11. The joint support device of claim 10, wherein saidspring is confined between a medial end of a pin fitting within saidpivot axle and securing the side plates to one another, and a medial endof the pivot axle.